Bedspring



Feb. 28, 1939. w. E. WUNDERLICH 2,148,88 9

BEDSPRING Filed April 2, 1936 Patente d Feb. 28, 1939 UNITED STATES PATENT OFFICE BED SPRING William E. Wunderlich, Mumie, Incl, assignor to The Moore Company, Mumie, Ind., a corporation of Indiana My invenbion relates 1:0 bed-spring assemblies{ or bed-bottoms, adapted support a mattress, and is particularly concerned with that type of spring assembly in which a series of rows of vertical compression springs have thei-r upper end turns tiecl together by di'agonally extending, crossed helical springs of relatively small diameter. One cf the problems 1:0 be met in the production of such a bed. bottom is the provision of satisfactory means for attaching each end of each helical spring to the associated upper end turn of a compression spring. For the sake of reduced production cost, it has been customary to form each end cf each helical spring with an eye or hook embracing the wire of the associated compression spring. A disadvantage ofsuch an arrangement is that relative movement of the upper ends of directly interconnected. compression springs, especially relative movement of such springs toward each o-ther, tends dislodge the hooks or eyes in I:he ends of ehe helical springs. 'Io prevent this it is customary 130 form each helical spring so that it is subjected to a considerable degree of longitudinal tension when in place in Order to maintain its hooks seated 011 the associated compression springs when such compression springs move toward each other. However, when the helical springs are subjected to sufiicient axial tension to prevent dislodgment of the hooks or eyes, ehe compression springs ab the edges cf the assembly are drawn inwardly with a force frequently sufficient to distort the border frame 130 which their end coils are connected.

lt is the object of my invention to overcome the above noted disadvantages of prior constructions.

More specifically, it is my objecb to form the heli cal springs with attaching hooks of such a shape and arrangement that they Will remain firmly seated in association With the compression springs irrespective of relative movement of the compressi'on springs and without the necessity for stressing the helical springs in such a way as to distort ehe borderframe cf the assembly.

In carrying out my invention I bend. the wire at each end of the helical springs to form an arcuate hook approximately 270 in angular extent ancl'clisposed approximately in a plane making an acute angle with'the immediately adjacent helical-wound pcrtion cf the wire. When the helical spring is in place in the assembly the wire cf the upper end turn of one cf the compression springs will pass through this hook to be snugly received in the acute angle just referred to. The hooks at the two ends of each helical spring are so re latively disposed about the spring-axis that when they are engaged with wires lying in the same plane the helical spring will be distorted torsionally in such a way that the elasticity cf the spring material will tend to force the engaged wire into tl1e acute angle between the b'ody of the spring and the hook and hold it there.

The accompanying drawing illustrates my invention: Fig. 1 is a fragmental plan view of a bed-bottom or spring-assembly; Fig. 2 is an elevation on an enlarged scale of one of the helical springs disassociated from the assembly and in unstressed conditi'on; Fig. 3 is a front elevation of I;he spring shown in sicle elevation in Fig. 2; Fig. 4 is an end elevation of the spring shown in Fig. 2; and Fig. 5 is a fragmental plan view generally similar to Fig. 1 but on an enlarged scale.

The spring-assembly illustrated in Fig. 1 comprises a suitable frame (not shown) to which are attachecl the lower ends of compression springs II] arranged in a series of parallel rows. Usually as indicated in the drawin, the compression springs Iil are either conical or hour-glass in shape and have their upper end. turns substantially co-planar. A border frame II surrounds the spring assemb-ly in the plane of the upper end turns of the springs I0 and. is securecl to the upper end turns of the outer springs. Within the border frame I I, the springs III are yieldingly held in proper relative position by means cf helical springs I2. These springs I2 are arranged in 30 pairs With the two springs in each pair threaded together so that they cross approximately perpendicularly, anal the two ends cf each helical spring are connected '00 the upper end turns of diagonally opposite compression springs II). As 5 above indicated, my invention relates particularly so the method by which the ends of the helical springs I2 are connected 1:0 the upper end turns cf the springs II].

As is clear from Figs. 2 3, and 4, the wire of each helical spring I2 is formeol als the end cf the spring in a hook I3 which is disposed generally in a plane at an angle 130 the axis of the helical' spring and has in iI3s plane, an arcuate shape of approximately 270 in extent. The angle between the plane cf the hook I3 and the immediately adjacent helically-wound wire-portion with which it is continuous is conveniently somewhat less than a right angle, as is clear from Fig. 2, 1:0 provide an acute-angle bend I4. The extreme end of 50 tl1e hook is formed to be approximately tangential to the last helical turn of the spring I2, as shown in Fig. 3, and to terminate near the point of tangency.

Each cf I:he springs I2 is formed to be substantially unstressed axially when in plane in the assembly. Provision is made, however, for insuring that each helical spring will be stressed torsionally when the hooks ab its opposite ends engage the co-planar end turns of two compression springs Hi. This result is secured by disposing the two hooks of each helical spring in the manner illustrated in Fig. 2. There, the hook at the lower end 0f the spring is shown as engaging an end turn of a compression spring I0 at a point where the wire oi such end. turn occupies a position substantially normal to the plane of the drawing. It is evident from Fig. 2 that in order for the hook ab the upper end of the spring I2 to engage a wire normal tothe plane of the drawing the upper end of the spring will have to be rotated (counterclockwise in Fig. 4) from the position illustrated. Such rotation of the upper end of the spring relative 1:0 the lower end will introduce a torsional stress serving to keep each hook firmly engaged With its assoeiated compression spring, the wire of which as theresu1t of the forces exerted upon lt by the hook, Will be forced to seat in ohe acute-angle bend M between the'hook and the body of the spring. A pair of crossed. helical springs I2 are shown in Fig. 5 as having the hooks at their ends thus seated in engagement with the upper end turns of compression springs I0.

With this arrangement, I find that relative movement of th-e upper ends of the springs H11 will not result in unseating the hooks or in causing the ends of the helical springs I2 to rlde over or under the end turns of the compression springs. A1: the same time, this result is seeured without subjecting the helical springs I2 130 axial tension sufficient in extent 170 distort the border frame l l.

In attaching an end of each helical spring the end turn of the associated. compression spring I0, the end of the helical spring is brought into association with the end turn of the spring 10 in the manner illustraoed in Fig. 4, where an end. turn o1 a compression spring is indicated. in dotted lines. In this position, the end turn of the compression spring is received between the body of the helical spring I2 and the free end of the hook I3; and. the helical spring is forced laterally of icself cause the free end of the hook 13 to pass over the wire of the compression spring which will then extend through the hook as indicated in the case of the hook at the lower end of the helical spring in Fig. 2. Preferably, the helical springs are so attached that the free ends of the hooks are beneath the plane of the upper surface of the spring assembly, where they can do no damage to a mattress supported on the assembly.

In the complete assembly, a portion of wlhich is shown in plan in Fig. 5, the bend I4 ab each end of each helical spring seats from below against the wire of the upper end turn of one of the compression springs. The hook I3, which passes through the plane of the end turn of the compression-spring, engages such compression-spring turn on its inner surface, while the outer suriace of the compression-spring turn is engaged. by the end. of the body of the helical spring. Thus provision is made for transmitting between the compression-spring turn and its associated helical spring forces in either direction along the axis of the helical spring. The hook !3, near its end, engages the compression-spring turn from above at a point spaced from the bend I4, whereby the torsional stress in the helical spring tends to maintain the bend I4 firmly seated on th-e wire of the compression-spring turn. As a result, the ends of each helical spring are compelled to fol- 1ow the upper ends of the associated compression springs in their relative movement, even when that relative movement is in a direction 130 shorten the helical spring; and any tendency of the end of the helical spring to ride over the compression-spring turn is effectively counteracted.

The extent 110 which the two ends of each helical spring must be rotated relatively to be brought into association with the co-planar end turns of associated compression'springs may vary widely. I have found a rotation of about 12 130 be satisfactory in the average bed-bottom now on the market.

I claim as my invention:

l. In a bed-bottom having a plurality of rows of compression s'prings provided With approximately co-planar end turns, openwound helical springs arranged in crossed pairs, the wire of each helical spring at each end thereof being formed into an arcuate hook disposed generally in a plane at an angle to the spring-axis and having near its extreme end a portion disposed approximately tangentially to the end of the body 0I the helical spring, the wire of the spring being bent ab an acute angle where the hook joins the boo'ly 01 the spring, the hooks at the ends of each helical spring engaging the end turns of diagonally opposite compression springs and being so relatively disposed about the axis of,the helical spring that when in place in the assembly the helical spring Will be torsionally strained to cause each 0f said acute-angle bends 110 be firmly seated on the associated compression-spring turn.

2. In a bed-bottom having a plurality of rows of compression springs provided with approximately co-planar end turns, openwound helical springs arranged in crossed pairs, tl 1e wire of each helical spring ab each end thereof being formed into an arcuate hook disposeol generally in a plane at an angle 130 the spring-axis, the wire of the spring being bent a1: an acute angle where the hook joins the body of the spring, the hooks at the ends of each helical spring engaging the end turns of diagonally opposite compression springs and being so relatively disposed about the axis of the helical spring that when in place in the assembly the helical spring will be torsionally strained 1:0 cause each of said acute-angle bencls to be firmly seated on the associated compression" spring turi1.

WILLIAM E. WIJNDERLICH. 

